rs727504336

Variant names:

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PM2

This summary comes from the ClinGen Evidence Repository: The NM_000257.3(MYH7):c.1477_1478delAT (p.Met493Valfs) variant has been identified in 1 individual with features of both HCM and DCM (Zimmerman 2010 PMID:20474083; Walsh 2017 PMID:27532257, LMM pers. comm.) however, this is insufficient to apply the PS4 criterion. This variant was absent from large population studies (PM2; http:// gnomad.broadinstitute.org, v.2.1.1). This variant is predicted to cause a frameshift leading to a truncated or absent protein. The contribution of loss of function (LOF) variants in MYH7 to autosomal dominant inherited cardiomyopathy is incompletely understood therefore PVS1 was not applied. In summary, due to insufficient evidence, this variant meets criteria to be classified as uncertain significance for cardiomyopathy in an autosomal dominant manner. MYH7-specific ACMG/AMP criteria applied (Kelly 2018 PMID:29300372): PM2. LINK:https://erepo.genome.network/evrepo/ui/classification/CA010796/MONDO:0004994/002

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)

Exomes 𝑓: 0.0000041 ( 0 hom. )

Failed GnomAD Quality Control

Consequence

MYH7
NM_000257.4 frameshift

Scores

Not classified

Clinical Significance

Uncertain significance reviewed by expert panel P:1U:3

Conservation

PhyloP100: 9.04

Variant links:

Genes affected

MYH7 (HGNC:7577): (myosin heavy chain 7) Muscle myosin is a hexameric protein containing 2 heavy chain subunits, 2 alkali light chain subunits, and 2 regulatory light chain subunits. This gene encodes the beta (or slow) heavy chain subunit of cardiac myosin. It is expressed predominantly in normal human ventricle. It is also expressed in skeletal muscle tissues rich in slow-twitch type I muscle fibers. Changes in the relative abundance of this protein and the alpha (or fast) heavy subunit of cardiac myosin correlate with the contractile velocity of cardiac muscle. Its expression is also altered during thyroid hormone depletion and hemodynamic overloading. Mutations in this gene are associated with familial hypertrophic cardiomyopathy, myosin storage myopathy, dilated cardiomyopathy, and Laing distal myopathy. [provided by RefSeq, May 2022]

MYH7 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 2 ACMG points.

PM2

For more information check the summary or visit ClinGen Evidence Repository.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MYH7	NM_000257.4 link	c.1477_1478delAT	p.Met493ValfsTer19	frameshift_variant	Exon 15 of 40	ENST00000355349.4	NP_000248.2	P12883
MYH7	NM_001407004.1 link	c.1477_1478delAT	p.Met493ValfsTer19	frameshift_variant	Exon 14 of 39		NP_001393933.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
MYH7	ENST00000355349.4 link	c.1477_1478delAT	p.Met493ValfsTer19	frameshift_variant	Exon 15 of 40	1	NM_000257.4	ENSP00000347507.3		P12883

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152158

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.000288

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.00

Gnomad OTH

AF:

0.00

GnomAD4 exome

Data not reliable, filtered out with message: AS_VQSR

AF:

0.00000410

AC:

AN:

1461886

Hom.:

AF XY:

0.00000550

AC XY:

AN XY:

727244

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.0000383

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.0000116

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00000360

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.00000657

AC:

AN:

152158

Hom.:

Cov.:

AF XY:

0.0000135

AC XY:

AN XY:

74326

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.000288

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.00

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.00000378

ClinVar

Significance: Uncertain significance

Submissions summary: Pathogenic:1Uncertain:3

Revision: reviewed by expert panel

LINK: link

Submissions by phenotype

Cardiomyopathy

Uncertain:2

May 12, 2023

CHEO Genetics Diagnostic Laboratory, Children's Hospital of Eastern Ontario

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Nov 30, 2021

ClinGen Cardiomyopathy Variant Curation Expert Panel

Significance: Uncertain significance

Review Status: reviewed by expert panel

Collection Method: curation

The NM_000257.3(MYH7):c.1477_1478delAT (p.Met493Valfs) variant has been identified in 1 individual with features of both HCM and DCM (Zimmerman 2010 PMID:20474083; Walsh 2017 PMID: 27532257, LMM pers. comm.) however, this is insufficient to apply the PS4 criterion. This variant was absent from large population studies (PM2; http:// gnomad.broadinstitute.org, v.2.1.1). This variant is predicted to cause a frameshift leading to a truncated or absent protein. The contribution of loss of function (LOF) variants in MYH7 to autosomal dominant inherited cardiomyopathy is incompletely understood therefore PVS1 was not applied. In summary, due to insufficient evidence, this variant meets criteria to be classified as uncertain significance for cardiomyopathy in an autosomal dominant manner. MYH7-specific ACMG/AMP criteria applied (Kelly 2018 PMID:29300372): PM2. -

Primary dilated cardiomyopathy

Pathogenic:1

Apr 26, 2016

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

proposed classification - variant undergoing re-assessment, contact laboratory -

Hypertrophic cardiomyopathy

Uncertain:1

Aug 07, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change creates a premature translational stop signal (p.Met493Valfs*19) in the MYH7 gene. It is expected to result in an absent or disrupted protein product. However, the current clinical and genetic evidence is not sufficient to establish whether loss-of-function variants in MYH7 cause disease. This variant is not present in population databases (gnomAD no frequency). This premature translational stop signal has been observed in individual(s) with clinical features of MYH7-related conditions (PMID: 20474083, 27532257). ClinVar contains an entry for this variant (Variation ID: 177817). In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.0

Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over